Simplify the following expression: $z = \dfrac{-9}{6k} + \dfrac{1}{6k}$
Solution: Since the expressions have the same denominator we simply combine the numerators: $z = \dfrac{-9 + 1}{6k}$ Combine like terms: $z = \dfrac{-8}{6k}$ Simplify by dividing numerator and denominator by 2: $z = \dfrac{-4}{3k}$